1. Technical Field
This invention relates to French drains and in particular to a device which can be used to replace the aggregate used in French drains or other water distribution systems.
2. Background Art
French drains are widely used in residential and commercial building applications to collect groundwater and distribute it away from the proximity of basements, foundations, footings, and similar surface and subterranean building structures where water may penetrate and/or damage these structures. An additional use of this technology is to deliver water into the sub-surface of the ground. For example, a French drain may be used to distribute fluid into the drain field of a residential septic system.
Various structures have been developed over the last two hundred years to accomplish this diversion of fluids. Generally, they consist of a pipe containing multiple small perforations throughout its sidewall through which water or fluid enters the pipe. The fluid then travels down the pipe to a desired location. To keep the perforations in the pipe from clogging, and to prevent dirt or other material from the surrounding substrate from entering the pipe, the pipe is laid within a bed of solid granular material that creates a porous aggregate unrestrictive to the flow of fluid, such as gravel, or a similar synthetic aggregate. Finally, a woven, coarse, landscape textile or filter fabric is used to surround and cover the aggregate to prevent the aggregate from becoming clogged with dirt or other surrounding substrate. The pipe, surrounding aggregate, and textile are typically installed within a trench which is then filled to grade level with dirt or other substrate. Rainwater or other surface water in the area seeps from the surrounding substrate through the textile where it may trickle freely through the aggregate into the pipe for removal from the area.
One significant problem with this system is the labor and expense necessary to surround the pipe with the aggregate. Also, if the aggregate is too heavy or is not placed carefully on top of the pipe, the pipe may break or collapse while the aggregate is being placed. This can cause time consuming and expensive problems.
Various inventions have been made in order to try and prevent these problems. For example, U.S. Pat. No. 5,810,509 issued to Nahlik, Jr. discloses a cell system for buried drainage pipes. These cells, however, cannot be used to form continuous French drains. Instead, there are individual cells that are spaced throughout the drainage area. These cells also do not protect the areas of pipe between the cells and therefore there may be a problem with these areas of pipe being damaged when the trench they are laid in is filled.
U.S. Pat. No. 7,191,802 issued to Koerner (hereinafter “Koerner”) and U.S. Pat. No. 5,051,028 issued to Houck et al. (hereinafter “Houck”), also attempt to improve French drains by replacing the standard aggregate. They, however, do not allow the aggregate replacement and pipe to be easily assembled on site.
Instead Houck discloses units that are manufactured as one piece with sections of perforated pipe inside. Multiple units are hooked together. Therefore if a section of pipe becomes damaged, the entire unit must be replaced rather than just the pipe.
Koerner discloses a system where netting filled with aggregate is wrapped along a perforated pipe. This system takes too long to conveniently assemble on site and therefore will likely need to be preassembled. Therefore if the pipe gets damaged the entire assembly will need to be replaced rather than simply replacing the pipe.
Also, while these patents claim to protect the pipe, in reality they would provide very little protection to the pipe when the trench is being filled in with substrate.
Accordingly, what is needed is an aggregate replacement device that is light weight, easy to use, quick to install and which allows the pipe to be accessed and inserted after the aggregate replacement has been placed in the trench.